Locomotive



1,6i8,23 J. L. MOHUN I Feb. .22 1927.

LOCOMOTIVE Filed'llarch 1. 192's 2 Shee'aSheet 1 Feb. v

J. L. MOHU N LOGOMOTIVE March 1. 1926 2 Sheets-Sheatz Patented Feb. 22, 192?.

UNITED mm BEST AVAILABLE ooev retain JOHN L. IVIOHUN, OF OMAHA, NEBRASKA.

LOCOMOTIVE.

Application filed March 1, 1926. Serial No. 91,380.

'lhis invention relates to lHlIH'OVQIHCIltS in locomotives and particularly to locomotives of high capacity for heavy service conditions. In ra'lway practice, there is a constant tendency. in the interest of economy. to\ 11rd increased length and tonnage of trains with the resulting demand for locomotives of increased capacity to meet these requirenients etiiciently under all service conditions. To

obtain the increased capacity of locomotives for this purpose necessarily involves increasing the size and weight of the locomotive correspondingly. There are necessarily 5 limitations to the height and width of locomotives on account of the restrictions dueto road clearances. The ])(l'l'lllS"ll-llt weight is also rertricted on account of the limitations in th carrying capacity of the usual rails. The weight of. the locon'iotive must be dis tributed uniformly over the rails and tor the heaviest rails now used the llltlXlll'HHH permissible weight per axle ot-the locomotive ranges from 55,000 to approximately (55.000 lbS.

To obtain a. thorough understanding of certain peculiar conditions which have been encountered in developing 'locon'iotives to keep pace with trains of constantly increasing length and tonnage, it is advisable to outlin. in brief. the developments which have taken place in locomotives and the characteristics of locomotives having the greatest. capacityand power consistent with economy prior to my invention as known to me.

As will'be well known to those skilled in this art, the earlier types of freight locomotives included the mogul, the ten wheel and the consolidation types. 'lhose u ed in pas-Niger service were the hi-(l or .\\nerican, the. -i--ti-t) or ten wheel type. and the 44-2 or the Atlantic type. liater came the'Mallet articulated type with two high and two low pressure cylinders which was followed by the 44-32 or la ilic type. and the Cole 't'our cylinder compound locomotive. The weights and tractive powers of the consol'dation were increased and the l inikado or Z d-2 also entered the field. The

Mallet type was also further developed and the arrangement varied from the 04543-0 type. and the 28-8-() type to the 2-lU--10-2 type. All types increaed in weight and power. Then followed the. mountain or 4-8-2 type, and the Santa Fe 01'2-10-2 type, the. Virginian or 210102 Mallet type. Other types involving, long rigid wheel bases were the 482, 2-10() and the 2-1042 types.

Even with the heavy rails now used permitting the maximiu'n weight per axle of from 55,000 to (35,000 lbs., and the long rigid wheel bases ofthe types of locomotives last referred to, it appeared that the limit in weight and power for a two-cylinder simple locomotive had been reached.

With the heavy reciprocating and rotating weights of the modern locomotive, the hammer blow on the rail of the weight reierred to. added to the driving wheel counterbalance to balance the reciprocating parts. has been a serious problem. It is therefore evident that the important problem in locomotive design is to increase the tractive power without materially increasing the weight on the individual drivers, to increase the boiler efficiency and to reduce the counter balance for recinrocatii'ig parts.

.ln increasing the size and weightct two cylinder locomotives to meet the require ments for more power. the limit was reached on account ot' the restriction imposed by road clearances, thus limiting the size of the cylinders which can be used. In increa ing the size of the cylinders. the piston thrusts also become eizceptionally high,

thereby placing the crank pin connections under excessive strain. In order to further increase the S IZ of locomotives and avoid the. difficulties pointed out, two additional cyl'nders were added, each pair of cylinders being associated with a separate articulated truck. The ,04545-0, 28-80, 2-1010-2 hereinhet'orejei'erred to. are of this type. The last-na1nhd construction has serious defects in that the arrangement of the second pair of cylinders rearwardly of the first. pair requires complex steam and exhaust connections for these cylinders.

Recently the three-cylinder locomotive has been developed wherein the three cylinders are all placed ka t the forward end of the locomotive, the third cylinder being located midway between the two 'side cylinders. Although experiments were made years ago with locomotives of the three cylinder type, it is only in recent years that they have gone into successful service in the United States. By providing the third cylinder between the other two cylinders, the total cylinder capacity of the t rec cylinder locomotive is great- 1y increased over the two cylinder type without interfering with road clearances. As the three cylinders are placed so as to operate 120 apart, itis evident that the weight of the reciprocating parts is greatly reduced and the hammer blow is also minimized. The

' counter balancing problem is also different than in the two cylinder type, whereby a great reduction in the weight of the rotating and reciprocating parts of each individual cylinder is had. \Vith the increased numher of exhaust impulses per revolution'in the locomotive of the three cylinder type, the

draft on the tire is also much more steady, particularly at low speeds. Due to the more uniform turning move-n'ient of the parts, a greater tractive power per pound of weight on the drivers is bad. An out tanding advantage is in the ability to handle trains when once in motion at a shorter 'cut ofl? than the two cylinder type. In the two'cylinder type, the arrangement of the cranks is such that the mean tractive effort will rise mate; rially. at one point in the revolution of the drivers and unless there is sutiicient weight on the drivers the latter will slip. In the case of the three cylinder arrangement, with the same cut-off and mean tractive eiiort, the

. increase will be materially less, requiring much less adhesiye weight to prevent slipping than the corresponding two cylinder desi n.

It will thus he seen that the three cylinder locomotive has a very high starting torque uniformly applied, thus reducing the stress on the draft gears and other parts and also that when the train is once in motion, it may behauled. at a much shorter "cut-off than with the two-cylinder type- On account of the counter-balancedcondition of the three-cylinder locomotive and the more even distribution ofthe piston imulses, the avera e boiler ressure is 1naintained better under all serv ce conditions.

The most successful locomotive of the heaviest three-cylinder type known to me prior to myginvention comprised ten driver; arranged in pairs mounted on a rigid base,

one ,mir ol drivers havin lateral motion.

' met.

One object of my invention is to provide a locomotive of exceptionally high capacity certain well-known types.

BEST AVAlLABLE COF\ and efliciency without exceeding the armissible weight per driver axle, which is economical In operation and capable of. moving heavy tonnage trains at high speed, thereby greatly reducing operating costs.

More specifically AIl OiflGCfi of my mvention is to provide adocomotive of high capac.

ity which will operate eflicientlyby an arrangement of cylinders all located at one end, associated-with a rigid wheel base, wherein the maximum number of drivers permissible with tracks of standard design and modern accepted weight are provided by permitting lateral movement of certain of the drivers.

Another object of my invention is'to provide a single steam locomotive unit of increased power over-existing locomotives of this type so designed as to provide greater boiler capacity per unit of traction than is attained in the single unit locomotive now in use, which conforms to accepted practice and at the same time is within existing limits of roadway clearances and doesnot overstress the present standard roadway.

. A still more specific object of the invention is to provide a locomotive of the type indicated having the cylinders at the front end thereof, provided with a rigid wheel base including twelve drivers arranged in pairs, the front and rear pairs of which have lateral motion, thus permitting the locomotive to pass over relativelv sharp curves in common use without undue strain on the roadwayand locomotive.

Other objects and advantages of the invention will more fully and clearly appear from the description and claims hereinafter following.

In the drawings, forming a part of th s specification, Figure 1 is a side elevational view of a locomotive engine embodying my improvements. Figure 2 is a front end elevational view of the locomotiveshownin Fi 1. Fi 3 is a also view of the running L t" i gear, partly broken away, showing the cylinders and wheel driving arrangement of the locomotive. Figure 4' is a detailed view of an equalizing mechanism provided for the leading truck, as sliownin Figure 5. Fig ure 5 is a partial side clevational view showing my improvements applied to a locomotive with a two-wheel leading truck. Fi ures 6 and -7-show two diagrams respectively illustrating thetractive power curves and locomotive as compared with locomotives of And Figure 8- is a longitudinal sectional View, broken away, of the forward end of the locomotive-illustrated in Figure 1.

Insaid drawings, A indicates the boiler of a locomotive, B the leading truck, C the running gear. As shown in the drawings, referring first to the embodiment of, the inthe operation facilitate the taking of curves.

BEST AVAILABLE com 1,61S,293- I vention illustrated in Figures 1 to 3, inclusive, the locomotive is provided with three cylinders l)---l)l). As shown, the cylinders COll'lPl'lSC a pair arranged at opposite sides of the locomotive and a third cylinder disposed midway between the former in a slightly inclined position. r

The wheel base of the locomotive has I! drive wheels 10 mounted thereon. As shown, the drive wheels 10 are arranged in six pairs and are coupled together for movement in unison by the side rods 11. front and rear pairs of drivers 10 are so arranged as to have acertain amount of lateral motion, lateral motion journal devices 12-12 being mounted on the truck frame, as most clearly shown in Figure 3. It will be evident that on account of the standard construction of curves of tracks now in gcnoral use, a locomotive having six pairs of drivers, none of which have lateral motion, could not be operated around the curved track sections, it being possible to' accommodate only a maximum of four or five pairs of drivers which are held against lateral motion on standard curves. For thisreason, I have provided the front and rear sets of drivers with lateral motion devices as hereinbefore pointed out. In Figures 1 and 2, I preferably provide an arrangement of drive as having the two center pairs blind, that is, not having flanges. In this manner, of the locomotive around curves is still further facilitated. It is also feasible to provide the two center pairs of drivers with lateral motion journals to It will be evident that although I have shown the two pairs of central'drivers as blind, this is not absolutely necessary as the locomotive will operate properly around curves which are not of excessive curvature even if all of the drivers are provided with flanges, so long as the front and rear pairs of drivers have lateral motion. The main rod of the central cylinder is designated by 13, and as shown is preferably connected with a crank member 14 provided on the axle of the second air of drivers. The other pair of cylinders is provided with the. usual main driving rods 15 which are connected to the usual crank pins 16,-the latter being preferably located on the third pair of drivers. The two outer cylinders D of the locomotive are located within theprescribcd limits of the standard road clearances now in use, and it will therefore be evident that by provid- -mg the third cylinder located between the outer pair, the amount of power is greatly increased over that which it is possible to obtain in two cylinder locomotives conforming to the standard road clearance restrictions. It will be evident. that inasmuch the size oftwo cylinder locomotives is limited on account of the existing clearwvcig it, with The of the the box auce limitations, it is impossible to obtain adequate cylinder power in a two cylinder locomotive without. exceeding these clearance limitations, and further as locomotives of the two cylinder ofc'linders involve added expense and l a consequent sacrilice of reduction in the boiler capacity, it will be evident that a great advantage is obtained by employing a single group of three cylinders. The further advantage of my improved design is that the middle cylinder is connected to one pair of drivers and the other cylinders are connected :0 a different pair of drivers, the crank pins of the two sets of drivers being so related as to operate approxunately 120 apart. By this arrangen'ient, maximum cylinder power within road clearance requirements is provided, less thrust is placed on each individual crank pin, and the arrangement of disposing, the crank pins 120 apart pgoduces a more even turning moment with less tendency of the drivers to slip than in the equivalent two-cylinder locomotive. A

' lower adhesive factor is thus permitted.

In the embodiment of the invention illus- (rated in l igures 1 to 3, inclusive, the locomotive is shown provided with a leading truck ll having four wheels. This truck, as shown, is disposed under the middle cylinder D and provides for a satisfactory distribution of the weighttive between the drivers and the .truck. However, by providing a suitable equalizing means, as shown in Figure 4, a two wheeled truck of the type shown in Figure 5 may be employed, the drivers being moved forwardly near the cylinders and the middle cylinder given a slightly greater inclination to the horizontal than inthe first form referred to. The trailer truck, which designated by E, ,in Figure 1 may have any number of wheels to suit the load carried on this truck. It will be understood that a truck similar to the truck E is also emploved in connection with the embodiment of the in vention illustrated in Figure 5.

In addition to the advantages of my improved locomotive over the prior art hereinbefore pointed out, by providing the six pairs of drivers, two of which-are laterals, an enormous increase in capacity over the ten wheel type of three cylinder locomotive heretofore in use is obtained. In addition to this, the eliicieucy is also materially increased over the three cylinder type referred to. By providing of drivers, the length of the boiler is materially increased, thereby also increasing the length of the fines of the boiler, the length and consequently greatly iucreasing the heating surfaces provided. With modern standard rails of the heaviest type now employed, the permissible weight types having two sets of the locomothe additional pair pointed out, ranges from comotive capacity. \Vith my the horizontal of the running gear to maintain the high tractiveell'rnt per axle of a locomotive, as hereinbefore 55,000 to' 65,000

ounds. In view of. this, it will be evident that the added pair of drivers means a decided additional. advantage in increased lo;

improved locomotive as hereinbefore described, a very efiicient tractive efiortis developed at low speeds and the maintenance of this tractive efl'ort at high speeds is substantiallyuniform. Compared with the best type of Mallet engine now in use, of substantially the same tractive effort as my improved three-cylinder type at three to five miles per hour, my improved-type of thrcc-cylinder locomotive will haul approximately twice the tonnage of the Mallet at 35 miles per hour. Inother Words, a tractive ettort of upwardly of 95,000 pounds within aspeed ran e of five miles an hour, and of substantial 45,000 pounds at 35 miles an hour is obtained by my improved design. This is graphically illustrated in the diagrams shown in Figures 6 and 7. In Figure (l,

,the horizontal lines indicate the tractive power in pounds and the vertical lines the speed in miles per hour. In Figure 7, the drawbar pull in pounds is indicated by lines, and the speed in miles per hour by the yertical lines. The tractive power curve of the Mallet locomotive referred. to is indicated by the line a-b in Figure 6, the tractive power curve of a similar Mallet locomotive'having 63 drivers is indicated by the line c-d in the same figure. The tractive power curve of my improved twelve driver, thrce-cylii'idcr locomotive is indicated by the line e-f in said figure, the curves representing the drawbar pull behind the tenders ot' the locomotives of these three types jcated respectively by the lines a-Z/, c d, and e"f in Figure 7.

The maintenance of high tractive cltort at high speeds in my improved locomotive is possible due to the fact that the weight is relatively light, thus permitting the use of a boiler ot' ample steam capacity to maintain these requirements, and at the same time remaining within the drivlng wheel weight limitations. The

inherent design of the Mallet engine referred 'to is such, that. it requires a relatively heavy running gear, including two sets (it c vlindcrs, pistons, valves, etc. The weight of these parts necessarilyrestricts the weight that may-he provided in the boiler and consequently aboilor' 0t ample steam capacity at high speeds is not possible without. exceeding the driving wheel weight limitations.

The advantage of my improved twelve driver type of locomotive over the best type of three-cylinder locomotive known to me prior to my invention, is graphically illusbeing' indi- BEST AVAlLABLE CUP:

trated by the diagrams in Figures 6 and'T. In these-ftliagrams, the tractive power curve and the draw-bar pull curve of the prior three-cylinder type hereinbeforereferred to" are designated respectively by g-'h and f-h. The threescylinder type of locomo tive referred to is provided with ten drivers arranged in pairs. As hereinbeforo pointed out, the advantages of my improved locomotivc over this type are due to the added length of wheel base, and increased boiler capacity, together with greater efficiency due to the larger area of the heating surfaces. At the same time, all the inherent advantages of the three-cylinder type of locomotive are retained.

It will be evident further that by my improved high capacity locomotive, trains of heavy tonnage may be handled at higher speed than heretofore, at the same time increasing the eliiciency and economy of the locomotive and greatly reducing operating costs.

While. I have herein shown and described what I now cpnsider the preferred manner of carrying out my invention, the same is merely illustrative. and I contemplate all changes and modifications that come within the scope of the claims appended hereto.

I claim:

1. In a single unit steam locomotive, operable on tracks of standard gauge and modern accepted weight, said locomotive including: frontand rear pairs of drivers having lateral motion, and a series of pairs of intermediate drivers, said series comprising at least four pairs of drivers, all of said drivers operating ,asra single unit; a set of driving cylinders all located forwardly of the drivers and operatively connected thereto, one of said cylinders being disposed between. the remaining cylinders and all of said, cylinders being confined within the clearance limits of present practice; and a boiler and accessory devices supported on said drivers, said boiler and devices together being of a totalweight proportionate to the standard total weightpermitted on all of said pairs of drivers, said boiler being of a size to deliver stcam to said cylinders in evenly sustained quantity throughout the range 1 of speed of the locomotive.

' 2. In a locomotive operable on tracks of standard gauge and weight, the combination with a boiler'including'othcr adjuncts; of a series of pairs of drivers supporting said boiler. said series including four pairs of drivers held against substantial lateral motion and additional pairs of drivers having lateral motion. all of said pairs of drivers being operatively connected and operating as a single unit, said boiler beingof a size and weight proportionate to the permissible standard carrying capacity of all of said parts of drivers combined; and at least three 130 release I BEST AVAILABLE 09m driving cylinders all located forwardly. of

said drivers and operativcly connected thereto.

3. In a locomotive'operable on tracks of standard gauge and weight, the combination with six pairs of drivers, said drivers being interconnected and operating as a single unit and having provision as to lateral motion as to some thereof, whereby to permit the locomotive to pass over curved tracks conforming to standard'practice; of a set of three driving cylinders for operating all of said drivers, all of said cylinders being located at one end of the locomotive and operatively connected to said drivers, said cylinders being conlincd within the clearance limits of present practice; and means supported by said drivers for supplying power to the cylinders including a boiler ot a size and capacity to deliver ample steam to provide maximum tractive effort throughout the speed. range of the locomotive, the total weight of said power means and cylinders being so proportioned as to not exteed the standard total carrying capacity for said drivers.

4. In a single unit steam locomotive 0perable on tracks of standard gauge and modern accepted weight, said locomotive including: six pairs of intercoupled drivers operating as a single unit and having provision as to lateral motion as to some thereof, whereby to permit the locomotive to pass over curved tracks conforming to present practice without excessive strain to'the locomotive or roadway; a Set of at least three driving cylinders all located forwardly of said drivers and operatively connected to the latter, said cylinders being confined within the clearance limits of present practice; and a boiler arranged to deliver steam to said cylinders in sustained quantity to provide for high tractive effort throughout the speed range of the locomotive.

5. In a single'unit steam locomotive operable on tracks of standard gauge and modern accepted weight, said locomotive including six pairsot' inter-coupled drivers operating as a single unit and having provision as to lateral motion as to some thereof, whereby to permit the locomotive to pass over curved tracks conforming to present practice without excessive strain to the 1000- motive or roadway; a plurality of driving cylinders all located forwardly of said drivers, one 01' said cylinders beingopera- I tivcly connected to one pair of drivers and the remaining cylinders being operatively as a single unit and having provision lateral motion as to some thereof, the wei on said drivers being maintained no (30,000 pounds perpair of drivers, a set at at least three cylinders for operating ali c said drivers, all of said cylinders being d posed forwardl of said drivers and optively connects thereto, said-cylinders or confined within the clearance limits or present practice; and a boiler of a capaciv characterized by the fact that it gener and delivers steam to said cylinders in s eient quantity to provide for a tractive a fort, on a levelfexceeding 95,000 poun within a speed range of five to eight m per hour, and substantially @5300 pounds a, 35 miles per h6ur.

7. A steam locomotive engine havin in. combination, three driving cylinders, six pairs of inter-coupled drivers operatio as a single unit, and means for providir eral motion to the front and rear drivers permit the engine to round curves witho undue strain on the engine or roadway.

8. A steam locomotive engine having, in combination, three driving cylinders pairs of inter-coupled-drivers operating as a unit, and means for providing lateral mo tion for the front and rear drivers to permitthe engine to round curves without 11 due strain on the engine or roadway, and power meansincluding a boiler so proportioned and arranged as to give the engine high tractive effort at high speeds.

9. A steam locomotive engine having, in combination, six pairs of intercoiipled driversv operating-as a single unit, tl'i driving cylinders, one of which is connected to one pair of drivers, and two of which are connected to another pair of drivers, and 22 leading truck dividing with the drivers the weight of the engine.

In witness that I claim the "foregoing I have hereunto subscribed my name this .I day of Februar 1926. 

